Hi I'm 37 Weeks About To Be 38 Weeks Pregnant

Hi I'm 37 weeks about to be 38 weeks pregnant on(Tuesday)feel very nausea and I haven't had a good bm for a week now lower back pain and I also have pregnancy diabetes but lately I don't eat much morning or afternoon but when it's dinner time I over stuff myself because I barley eat during the day but now every time I ear or drink it feels like it wants to come up what should I do?